Comment 52 for bug 212648

http://ubuntuguide.org/wiki/Ubuntu:Gutsy#disablectrlaltconsole does that too.

I'm running 32 bit version of Ubuntu 8.04, upgraded from 7.10. For some reason it doesn't happen if I use firefox 2 instead of the 3 beta, so I'm using that as my main web browser while waiting for a bug fix.